Function _array_descr_walk_subarray

numpy/core/src/multiarray/hashdescr.c:193–227

* Walk into subarray, and add items for hashing in l * * Return 0 on success */

 * Return 0 on success
 */
static int _array_descr_walk_subarray(PyArray_ArrayDescr* adescr, PyObject *l)
{
    PyObject *item;
    Py_ssize_t i;
    int st;

    /*
     * Add shape and descr itself to the list of object to hash
     */
    if (PyTuple_Check(adescr->shape)) {
        for(i = 0; i < PyTuple_Size(adescr->shape); ++i) {
            item = PyTuple_GetItem(adescr->shape, i);
            if (item == NULL) {
                PyErr_SetString(PyExc_SystemError,
                        "(Hash) Error while getting shape item of subarray dtype ???");
                return -1;
            }
            PyList_Append(l, item);
        }
    }
    else if (PyLong_Check(adescr->shape)) {
        PyList_Append(l, adescr->shape);
    }
    else {
        PyErr_SetString(PyExc_SystemError,
                "(Hash) Shape of subarray dtype neither a tuple or int ???");
        return -1;
    }

    Py_INCREF(adescr->base);
    st = _array_descr_walk(adescr->base, l);
    Py_DECREF(adescr->base);

    return st;
}

/*
 * 'Root' function to walk into a dtype. May be called recursively